The findings marked the first quarter in nine years that a company other than Samsung or Apple has led the market, Canalys said.
"Our business has demonstrated exceptional resilience in these hard times", Huawei has said in a statement. This is most likely due to the dominance Huawei in the Chinese market, but that is largely irrelevant now.
Another victor in the second quarter was Apple, which finished fifth in China, as the US tech giant achieved the highest year-on-year smartphone shipment growth of 35% with 7.7 million units.
However, Canalys Analyst Mo Jia said: "Taking first place is very important for Huawei".
China took an early hit from the coronaviruspandemic but has since reclaimed ground as new cases have dwindled.
Restrictions apparently had a big impact on Huawei's sales overseas, which decreased by 27%.
Huawei's 55.8 million shipments are 5% lower than this time a year ago, but that's not enough to stop it taking the top spot for the first time. It's unlikely Huawei will be able to maintain its position as the global economy recovers, with retailers in countries outside China increasingly wary of stocking the company's products.
Vivo, Oppo and Xiaomi posted second-quarter smartphone shipments of 14.8 million units, 14.5 million units and 9.3 million units, respectively.
A total of 285 million smartphones were shipped across the world.
The British government bowed to growing USA pressure and pledged earlier this month to remove Huawei from its 5G network by 2027, despite warnings of retaliation from Beijing. The company continues to struggle against mid-range competition from Chinese OEMs in many markets.
Earlier this month, the United Kingdom government revealed that Huawei equipment will be banned from the UK's 5G networks due to security concerns. So for all intents and purposes, it's business as usual for Huawei in the country, and with the market accounting for 369 million phone shipments in 2019, there's plenty of room for Huawei to grow. Huawei's figures were nearly exclusively boosted by sales in its native China, which now comprises more than 70% of its total figure.
A years-long U.S. pressure campaign against Huawei has handicapped the Shenzhen-based firm's global business.
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